STORY ARCHIVE

Future of Fusion

Nuclear fusion - where energy is obtained by joining atoms together rather than splitting them as they are in the more conventional fission reactor  promises to provide unlimited clean energy for the future. Graham Phillips heads to Europe to find out just where nuclear fusion research is at.

TRANSCRIPT

Narration The Sun is seen as Nature's ultimate energy source. Because most power is actually re-versioned solar. The power of the wind, ultimately comes from the Earths uneven heating by the sun. Hydroelectricity is driven by the water cycle, which in turn is driven by the sun. Even the ancient life that become fossil fuels grew because of the suns energy.

Prof. John HowardAll the renewable sorts of energy sources ultimately come from the sun.

NarrationBut in the bigger picture Mother Nature has a more fundamental energy supply... one that powers every star in the cosmos including our sun... nuclear fusion.

Dr Barry GreenFusion reactions are fundamental to the make up of the universe. The coming together or fusion of light nuclei to form heavier nuclei with the liberation of lots of lovely energy.

NarrationIn the sun, nuclei of the lightest element of all  hydrogen  are fused to form the second lightest  helium.

Dr Boyd BlackwellIt's quite difficult to force them close enough, but once they're together, they'll fuse together and there's a little bit less mass in the end product than there was to start with and Einstein's equation E=MC2 says you've converted that into energy. Lots of energy.

Man in streetOh ye, oh ye! Welcome to the City of Oxford.

NarrationReleasing this cosmic energy down here on Earth, creating power station, is the goal of fusion research. And just down the road from this old-world town physicists are experimenting with futuristic technologies they hope will do it. And what a power station is promised.

Dr Graham Phillips A large coal-fired power station burns through more than 2 million tonnes of coal each year. Now imagine the same sized power station but one that goes through 500 kilograms of fuel. And, further image that fuel is so abundant it can power humanity's needs for millions of years to come  and there are no carbon emissions. It would be the perfect solution to today's environmental and energy woes.

NarrationThis is the largest fusion reactor built to date... JET the Joint European Torus. It's been creating fusion power for almost two decades.

Dr Barry GreenWe produced in 1991 the first significant amount of fusion power, which was about two megawatts over a period of about two seconds. Now that for us was a large amount of power.

NarrationBut here's the problem. For every reactor built so far, the machine consumes more power than it creates. They're hardly power stations. But that may be about to change.The JET reactor is now being used as a test bed to build an even bigger machine known as ITER. It should achieve that holy grail of fusion research... more power out than in.

Dr Barry Green That will produce, hopefully, 400 to 500 megawatts of power for a significant amount of time.

NarrationITER is just starting to be built in the south of France and will be finished by 2020. It should be the last experimental reactor before a full demonstration commercial fusion power station is built.

Dr Barry GreenWhile we can't contribute to the energy crisis immediately, by the middle of this century, if there was enough political will to do so, we could certainly have commercial reactors up and running.

NarrationDeuterium is the form of hydrogen the reactor needs. It's just hydrogen with an extra neutron added. The other form of hydrogen needed is tritium: a hydrogen atom with two extra neutrons. These two are squeezed together to create helium and release energy. The tritium is obtained from lithium - again an abundant element on Earth.

Dr Boyd BlackwellIt's the energy source for the third millennium. That will certainly supply base-load energy in essentially unlimited quantities  millions of years of energy  with no carbon output.

NarrationFor fission reactors, nuclear waste has to be stored for thousands of years, but the lower level waste from a fusion machine would only need 100 years.

Dr Barry GreenWe can manufacture the reactor of materials which could be recycled if that was economically desirable within a hundred years.

NarrationSo what's holding us back from tapping into the cosmos's energy? Three challenges. Number one... squeezing hydrogen atoms together in sufficient numbers for sufficient time to start the fusion process. On the sun it's done by gravity.

Prof. John HowardOn Earth we don't have access to that gravitational force so we have to use magnetic forces.

NarrationA magnetic force field in the shape of a bottle is created to squeeze together the hydrogen ions in the reactor plasma.

Dr Graham PhillipsThis device demonstrates the basic principle of a magnetic bottle. Inside is a plasma: positive nitrogen ions and negative electrons, and this is just a regular bar magnet. And as I bring it into contact with the plasma, the plasma is attracted towards it. Now I can just spin the magnet around and you can push the plasma away, so you can imagine, with a whole series of magnets pushing and pulling in just the right way you can restrain the plasma to be just where you want it.

Prof. John HowardBut Nature conspires to make it difficult. Trying to hold these high-pressure fusion plasmas using a magnetic bottle is akin to trying to hold a bowl of jelly with elastic bands.

NarrationOn ANU's stellerator it's done by placing magnets in just the right positions around the outside.

Dr Boyd BlackwellThis is one of 41 magnets to create a very special plasma shape. Our total magnetic field is 5000 times the Earth's magnetic field and we put currents of 14,000 amps through this lower vertical field here.

Dr Graham PhillipsOk, so those magnets are part of creating that magnetic bottle.

Dr Boyd BlackwellYeah they're essential to it.

NarrationDespite being tricky, physicists say the magnetic bottle problems are largely solved... but it's a different story for the physical container the reaction chamber holding the plasma.

Dr Graham PhillipsNow very deep inside all this equipment is the actual reaction chamber that's where the nuclear fusion actually happens. Basically the chamber is shaped like a 7-metre wide donut. Now when this machine is turned on, the temperature inside is a hundred million degrees Celsius. That's 20,000 times the surface temperature of the sun.

NarrationAnd this is the second great challenge: finding materials that can deal with such extreme conditions. The chamber walls are also bombarded by neutron radiation. The tiles on JET's chamber walls have to be replaced with remote handling equipment.

Remote handling operatorSo this is so we can work in contaminated areas. We'll be stripping all the internal tiling from the inner and outer vessel and will be replacing it with a new design.

NarrationOperating the equipment is difficult and replacing the tiles expensive... more durable tiles need to be found.

Dr Barry GreenWe have a lot of people around the world who are looking at different materials and irradiating materials with neutrons to make sure that they retain their physical properties. The people who are doing this are more and more confident that we will find materials to do the job.

NarrationAnd the final great challenge is maintaining financial support for fusion research.

Dr Barry GreenThis is a long term research and development project. And therefore to maintain the support  the political and financial support is quite an issue because normally people who pay for research like to see returns immediately  or yesterday.

NarrationBut you'd think unlocking the universe's fundamental energy should be a very high priority given our current environmental and energy problems.

Prof. John HowardWell I think ultimately it's the only answer. I don't thing human beings really have an alternative. So it's not a question of should we, it's a question of when can we.

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YOUR COMMENTS

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Physics Teacher - 09 Mar 2010 5:21:45pm

As a teacher who uses catalyst episodes as a teaching resource, I would be very interested in when the ABC will make episode 2 on Nuclear Fusion available for download. The insights presented will prove interesting and valuable to my students. So MyABC, please hustle :-)

Moderator: Download episodes of Catalyst, including episode 2, using the WMV and MP4 links at: http://www.abc.net.au/tv/geo/catalyst/vodcast/default.htm

nobody in particular - 01 Mar 2010 2:21:49am

Where's the vodcast? Straight from ep 1 to ep 3?

Nathan Bolstad - 28 Feb 2010 10:16:32pm

There seems to be a lot of international discussion surrounding the brute force approach to fusion that the ITER is following, but very little when it comes to more novel approaches to achiving fusion.

Once such approach, which to me seems promosing (simply from the rapid progress of the project) is the Focus Fusion Society (FFS) work.

If their timeline holds, we may well see fusion within a few short years (far sooner and cheaper than ITER would deliver).

Bevan Dockery - 24 Feb 2010 12:43:29am

I was appalled to hear the comment about nuclear fusion that it would produce "no carbon emissions. It would be the perfect solution to today's environmental and energy woes". If global warming is with us, the problem is not carbon but heat. Carbon is the fourth most common element in the universe. Our bodies are 18% carbon. Our problem is the balance between the incoming sun's radiation and the outgoing heat from the earth. If we start adding large quantities of heat via nuclear fusion we will be in big trouble. To date mankind has not shown any inclination to moderate his demands on the earth. Abundant energy from nuclear fusion could cause runaway demand for energy and we really would have extreme global warming.

Arthur Robey - 25 Feb 2010 11:09:16pm

The solar constant (the amount of energy the earth receives from the sun is 1336 watts per square meter.Multiply that by the cross sectional area of the planet in square meters and it will become obvious that the energy from the sun dwarfs anything that us humans produce. I wouldn't take ourselves too seriously.On the other hand the consequences of too much carbon dioxide in the atmosphere are significant.The sun has turned hydrogen to helium. Helium is a greenhouse gas for the sun.In 4.5 billion years the solar constant has increased 20%. Life on the planet has compensated for this increase by sequestering carbon dioxide out of the atmosphere. We are now down to 4%. It is near impossible for the plants to pull any more out. The failure of this feedback loop has led to temperature instability, in the form of the Ice ages. Now is not a good time to be pouring carbon back into the air.We are flirting with the inner edge of the Goldilocks Zone around the Sun.

L Bateman - 25 Feb 2010 11:45:46pm

Try reading the poem "Said Hanrahan" by John O'Brien!!!

Anton Lang - 19 Feb 2010 11:25:02am

Each week I eagerly look forward to watching Catalyst, because it is a wonderful way of bringing Science to the masses.This Fusion story is really interesting, and in fact the potential of the availability of limitless amounts of electrical power is something that should make us all sit up and take notice.However, I would like to point out an error that was made by the presenter, Dr Graham Phillips, and this is not meant to detract from the overall intent of this story.

As he was walking the streets of Oxford, and at around the 2.50 mark in the clip, he mentioned that a large coal fired power plant burns more than 200 million tons of coal a year.When I heard that it immediately made me sit up and take notice, and then chase up this clip at your wonderful site, because I felt almost certain that he would not make such a glaring mistake, so I put it down to the fact that I had actually misheard what he said.However, when I did check, he in fact was unequivocal in what he did say.If it was close, then an error like this might be understandable, but an error of this magnitude may tend to portray a false impression.

The largest of coal fired power plants will burn on average between only 6 million and 7 million tons a year, positively nowhere near the 'more than 200 million tons' quoted by Graham.In fact, in the whole of the U.S. the yearly total for the whole coal fired inventory for every coal fired power plant is just under 950 million tons, as shown at this link to the U.S. Government's own site.

http://www.eia.doe.gov/cneaf/electricity/epm/table2_1_a.html(shown at the bottom left of the chart)

I understand this may seem picky of me to point this out, but if the 'average punter viewer' sees this, then it might engender a false belief.I know that no one will come here to read this, so even mentioning it is probably a fruitless exercise, but I just thought I would bring this to your attention, as it is such a glaringly huge error of fact.

Again, thank you for your wonderful weekly program. It's just so good to see that at least someone thinks that a program of this nature can actually prove popular, as it has, and in its many forms over the decades, with Quantum before it, and even before that the Science program that started on the ABC and then went to the Commercials.Anton.

Moderator: Dear Anton,thank you for showing us this factual error. It has been changed in this story's transcript and we are currently working at correcting this in the video, which will be re-posted on the website very soon.

Best Regards

Catalyst

Jps - 19 Feb 2010 12:39:50am

As an ANU physics/engineering graduate I'm glad to see your plasma research is getting further publicity. Keep up the great work!